import org.eclipse.jdt.annotation.NonNull; import org.eclipse.jdt.annotation.Nullable; public class NullAnnotatedFields { @NonNull Letter nonNull; @Nullable Letter nullable; String test() { nonNull.print(); nullable.print(); nonNull = null; if (nullable != null) nullable.print(); // protected nullable = new Letter(); bar(); // spoils protection return nullable.toString(); } void bar() { } } // --- not shown in the screenshot: --- class Letter { void print() {} }